<template>
	<view class="main-content" :style="[canvasStyle]" v-if="isShow" @touchmove.stop.prevent="">
		<!-- 签字canvas -->
		<canvas class="mycanvas" :style="[canvasStyle]" id="mycanvas" canvas-id="mycanvas" @touchstart="touchstart"
			@touchmove="touchmove" @touchend="touchend"></canvas>
		<!-- 旋转canvas -->
		<!-- :style="{ 'z-index': -1, width: `${screenWidth}px`, height: `${(screenWidth * screenWidth) / screenHeight}px` }" -->
		<canvas class="mycanvas mycanvaspo"
			:style="[{ 'z-index': -1},canvasStyle]"
			id="rotatCanvas" canvas-id="rotatCanvas"></canvas>
		<cover-view class="button-line" v-if='btnShow'>
			<cover-view class="save-button" @tap="finish">保存</cover-view>
			<cover-view class="clear-button" @tap="clear">清除</cover-view>
			<cover-view class="cancel-button" @tap="hide">关闭</cover-view>
		</cover-view>
	</view>
</template>

<script>
	export default {
		props: {
			btnShow: {
				type: Boolean,
				default: false
			},
			canvasStyle: {
				type: Object,
				default: () => {
					return {
						width: '100vw',
						height: '100vh'
					}

				}
			}
		},
		data() {
			return {
				ctx: '', //绘图图像
				points: [], //路径点集合
				isShow: true,
				screenWidth: '',
				screenHeight: ''
			};
		},
		mounted() {
			this.createCanvas();
			uni.getSystemInfo({
				success: e => {
					this.screenWidth = e.screenWidth;
					this.screenHeight = e.screenHeight;
				}
			});
		},
		methods: {
			show() {
				this.clear();
				this.isShow = true;
			},
			hide() {
				this.isShow = false;
			},
			//创建并显示画布
			createCanvas() {
				this.showCanvas = true;
				this.ctx = uni.createCanvasContext('mycanvas', this); //创建绘图对象
				//设置画笔样式
				this.ctx.lineWidth = 2;
				this.ctx.lineCap = 'round';
				this.ctx.lineJoin = 'round';
			},
			//触摸开始，获取到起点
			touchstart(e) {
				let startX = e.changedTouches[0].x;
				let startY = e.changedTouches[0].y;
				let startPoint = {
					X: startX,
					Y: startY
				};
				this.points.push(startPoint);
				//每次触摸开始，开启新的路径
				this.ctx.beginPath();
			},
			//触摸移动，获取到路径点
			touchmove(e) {
				let moveX = e.changedTouches[0].x;
				let moveY = e.changedTouches[0].y;
				let movePoint = {
					X: moveX,
					Y: moveY
				};
				this.points.push(movePoint); //存点
				let len = this.points.length;
				if (len >= 2) {
					this.draw(); //绘制路径
				}
			},
			// 触摸结束，将未绘制的点清空防止对后续路径产生干扰
			touchend() {
				this.points = [];
			},
			/* ***********************************************
				#   绘制笔迹
				#	1.为保证笔迹实时显示，必须在移动的同时绘制笔迹
				#	2.为保证笔迹连续，每次从路径集合中区两个点作为起点（moveTo）和终点(lineTo)
				#	3.将上一次的终点作为下一次绘制的起点（即清除第一个点）
				************************************************ */
			draw() {
				let point1 = this.points[0];
				let point2 = this.points[1];
				this.points.shift();
				this.ctx.moveTo(point1.X, point1.Y);
				this.ctx.lineTo(point2.X, point2.Y);
				this.ctx.stroke();
				this.ctx.draw(true);
			},
			//清空画布
			clear() {
				this.ctx.clearRect(0, 0, this.screenWidth, this.screenHeight);
				this.ctx.draw(true);
			},
			//完成绘画并保存到本地
			finish() {
				uni.canvasToTempFilePath({
						canvasId: 'mycanvas',
						success: res => {
							console.log(res);
							this.rotat(res.tempFilePath);
						},
						complete: com => {}
					},
					this
				);
			},
			// 将图片选装
			rotat(e) {
				let rotatCtx = uni.createCanvasContext('rotatCanvas', this); //创建绘图对象
				// 重新定位中心点
				// rotatCtx.translate(0, (this.screenWidth * this.screenWidth) / this.screenHeight);
				// 将画布逆时针旋转90度
				// rotatCtx.rotate((270 * Math.PI) / 180);
				// 将签字图片绘制进入Canvas
				// rotatCtx.drawImage(e, 0, 0, (this.screenWidth * this.screenWidth) / this.screenHeight, this.screenWidth);
				console.log(this.screenWidth);
				rotatCtx.drawImage(e, 0, 0, this.screenWidth-70, this.screenHeight/2);
				// 保存后旋转后的结果
				rotatCtx.draw(true);
				setTimeout(() => {
					// 生成图片并回调
					uni.canvasToTempFilePath({
							canvasId: 'rotatCanvas',
							success: val => {
								console.log(val, '2');
								this.$emit('tempFilePath', val.tempFilePath);
								setTimeout(() => {
									// this.hide();
								}, 500);
							},
							complete: com => {
								// console.log(com);
							}
						},
						this
					);
				}, 500);
			}
		}
	};
</script>

<style lang="scss" scoped>
	.main-content {
		// width: 100vw;
		// height: 100vh;
		background-color: red;
		// position: fixed;
		top: 0rpx;
		left: 0rpx;
		z-index: 9999;
	}

	.mycanvaspo {
		width: 100vw;
		height: 100vh;
		// canvas背景颜色
		background-color: #efefef;
		background-color: #FFF;
		position: fixed;
		left: 0rpx;
		top: 0rpx;
		z-index: 2;
		}

	.mycanvas {
		// width: 100vw;
		// height: 100vh;
		// canvas背景颜色
		// background-color: #efefef;
		background-color: #FFF;
		// position: fixed;
		left: 0rpx;
		top: 0rpx;
		z-index: 2;
	}

	.button-line {
		transform: rotate(90deg);
		position: fixed;
		bottom: 170rpx;
		left: -100rpx;
		width: 340rpx;
		height: 50rpx;
		display: flex;
		align-items: center;
		justify-content: space-between;
		z-index: 999;
	}

	.button-style {
		color: #ffffff;
		width: 100rpx;
		height: 60rpx;
		text-align: center;
		line-height: 60rpx;
		border-radius: 10rpx;
	}

	.save-button {
		@extend .button-style;
		background-color: #02b340;
	}

	.clear-button {
		@extend .button-style;
		background-color: #ffa500;
	}

	.cancel-button {
		@extend .button-style;
		background-color: #e10b2b;
	}
</style>